Visrom I guess we'd simply have to agree to disagree on whether Gandhari was a sinful woman or not - and indeed, @ the end of the day, that's a subjective opinion, whoseever it is.
I know that people can argue about versions, and the one I used is the most detailed one online -
that of KM Ganguly. The other major version is the P Lal transcreation, which I admittedly don't have. It's said to have some minor variances w/ the KMG version, and whether Gandhari is one of them, I don't know.
Anyway, on your question about whether Gandhari's curse would have worked had she been sinful, the answer is - why not? Usually, devotion to either Brahma or Mahadeva was enough to give demons enough powers - including spiritual - to do a lot of things. Most famous example - Ravan. Gandhari got all her powers b'cos of her single-minded devotion to Shiva. That was completely independent of her attitude and actions towards her family. As for the villains in our epics, most of them were so happy w/ being able to entertain themselves physically that the idea of cursing their enemies simply never occured to them - more often than not, they'd consider it the act of weaklings and cowards.
On her curse to Krishna, reason it worked was that
Krishna himself wanted it to work. He was aware that due to the sense of security of living under him, his people had grown vain and arrogant, and so he didn't want to leave them as a burden on bhulok. With each of his wives, he had 10 sons and a daughter, and that would have meant 1,61,080 princes on earth, which would have been too much. Also, one version has it that he knew that (like the people of Ayodhya did when Rama left), his people wouldn't be able to bear separating from him, so he decided to pre-arrange their end. Personally, I don't consider this last explanation credible, as it begs the question of why did he send Daruka to bring Arjun and take the survivors back to Mathura - he could have simply let them drown w/ the city itself: but he did want those who were young and innocent to be saved, and given a new future, which Arjun did. But long story short, Krishna wanted his race decimated for at least the first of the above reasons, and the curses by both Gandhari and the rishis later were vehicles to enable that to happen.
The BRC version may be good enough for you, and that is fine. As long as one recognizes that it was hugely @ variance w/ Vyasa's epic, I am fine. One author - PN Vartak - wrote several volumes of how the serial differed from the original. Just one example - Duryodhan never in his life got to know who Karna really was. That was a
huge distortion. You are right that there are a lot of versions, but the one which I liked above - Kisari Mohan Ganguly - is one of the first complete English translations of the original epic that one can find. There is some discussion about that on the first 5 pages of this thread -
+* Dwapar Yuga: Doubts & DiscussionsOn the ACKs, every one of them tends to glorify their subject, except a few like Lord of Lanka (for Ravan). So they painted Gandhari in that manner. Incidentally, even that ACK, if I recall right, had that account of Gandhari prematurely expelling her fetus and getting a dead mass of flesh, so in that sense, they were right.
On Draupadi, I've never read about her not having any sons. But one thing - don't remember whether it was you or someone else who mentioned that she too had her faults - indeed, she did. Initially, she was jealous of Subhadra and gave Arjun an icy welcome when he returned w/ her. There was also one story of how Krishna forced her to admit to everyone that she had a secret desire to have Karna as her 6th husband. During their final journey to swargalok, when she was the first to fall and die, Yudhisthir explained to a shocked Bhima that even though she was the wife of all of them, she had a minute preference for Arjun, due to which she wasn't able to attain swargalok in her human form. But bottom line - even though Draupadi had her faults, she was not evil - unless one holds against her her desire to tie her hair w/ Dushashan's blood (incidentally, I'd have to re-check whether she actually
did make such a vow - I don't recall Bhima leaving the battlefield and giving her Dushashan's blood to use as hair softener.)
Having said all that, I agree to disagree w/ you, and let you believe BRC if that's what you so desire. I just thought it important to point out things that were not in the original, as well as address the notion that if one was otherwise sinful, one didn't have much spiritual powers.